The Occupational Safety and Health Administration, or OSHA, requires that the colors of a safety vest, which are typically bright red, yellow, neon green or orange, contrast significantly from the surrounding area so the wearer stands out. Safety vests also frequently have reflective material so wearers are visible from at least 1000 feet to cars driving by at night.
While OSHA requires reflective material on safety vests worn at night, there is not a specific requirement about the type of reflective material or how the vest fastens. Grainger Industrial Supply recommends that safety vests worn on a daily basis not be used for more than six months, because the vest loses reflectivity the more it gets used and the dirtier it gets. The vest therefore needs to be clean for best results.
The American National Standard for High-Visibility Safety Apparel and Headwear also requires that safety vest manufacturers include labels on the inside of the vests that specify the performance classification number and a drawing of the vest. There are three levels of performance classification, based off the amount of reflective material on the vest, the amount of background material and the overall visibility. Certain jobs, such as flaggers or emergency responders, require the highest level of performance classification. Workers such as shopping cart retrievers can use lower classifications.